fire iron vs fire tongs

fire iron and fire tongs both are nouns.

Word	Noun	Adjective	Verb	Adverb
fire iron	Yes	No	No	No
fire tongs	Yes	No	No	No

As nouns, fire tongs is a hyponym of fire iron; that is, fire tongs is a word with a more specific, narrower meaning than fire iron:

Other hyponyms of fire iron include coal tongs, fire hook, poker, salamander, stove poker, shovel.

fire iron (noun)	fire tongs (noun)
metal fireside implements	tongs for taking hold of burning coals